Process for continuous impregnation of cables and the like articles



Sept 5, 1944.

F. PEEL ET AL PROCESS FOR CONTINUOUS IMPREGNATION OF CABLES AND THE LIKE ARTICLES Filed April 29, 1940 2' Sheets-Sheet l gradua QdV/M Sept. 5, 1944. F. PEEL ET AL. 2,357,686 PROCESS FOR CONTINUOUS IMPREGNATION OF CABLES AND THE LIKE ARTICLES Filed April 29, 1940 v 2 Sheets-Sheet .2

Patented Sept. 5, 1944 PROCESS FOR CONTINUOUS IMPREGNA- TION F CABLES AND THE LIKE ARTI- CLES Frederick Peel, Gidea Park, and Russell Swale Vincent, London, England, assignors to Callender's Cable & Construction Company Limited, London, England, a British company Application April 29, 1940, Serial No. 332,380 In Great Britain May 13, 1939 3' Claims. (Cl. 117-61) This invention relates to an improved process for continuous impregnation of cables and the like articles. One of the principal objects of the invention is to provide improved outlet glands for removing the cable from a treatment zone which is under vacuum or under superatmospheric pressure, i. e. in either case at a pressure other than atmospheric. A further object of the invention is to provide improved means of impregnating cable under superatmospheric pressure. Further objects will appear from the following description and the scope of the invention will be defined in the claims. method of treatmentoi cables is that described in co-pending application No. 253,454 of R. S.-

The general pending application No. 253,454 which zones may be entered through a dry gland. The cable passes over the pulley 2 and through the elongated pipe 3 which may be under vacuum, and

then over pulley 4 through the viscosity glands 5 and 6 connected by the intervening vessel I. Liquid leaking through the gland is passed by pump 8 into the pressure zone 9. The cable emerges through the viscosity glands l0 and H and in intermediate vessel I2 from which liquid is returned to the pressure zone through the pump i3. Additional means may be provided for bly the impregnating liquid itself. It is preferred venient when pressure and vacuum treatments are to be alternated.

The invention also includes the provision of means to heat the air surrounding the dry gland at the inlet. This reduces the total mass of air which leaks through the gland partly because of the lower specific-gravity of hot air as compared with cold air and partly because the volume of leakage is reduced since hot air has a viscosity greater than that of cold air. This heating may be effected by an electrically heated tube.

The invention will be illustrated by way of example in the accompanying drawings which represent diagrammatic vertical sections through suitable apparatus. For details apart from the viscosity gland and impregnation under super atmospheric pressure reference may be made to co-pending application No. 253,454.

In Fig. 1, is the cable which is passed through a treatment zone or zones '(not shown), as in coincreasing the pressure in' the impregnating zone 9 if desired.

Fig. 2 shows a similar arrangement in which the final pressure zone is not employed. In this case the cable l4 which may have been impregnated under vacuum as described in copending application No. 253,454 enters a vessel 5 containing a pulley I6 and then passes through the viscosity glands I1 and I8 separated by an intervening vessel l9 provided with a pump 20. The cable emerges into the tank 2| which is open to the atmosphere.

Fig. 3 is a detail of the arrangement of the viscosity glands 22 and 23 where 24 is the intervening'vessel and 25 is the pump which returnsthe liquid through a pipe 26 to a pressure impregnating zone 21 containing liquid impregnating composition. The gland tube 23 is surrounded by a cooling jacket 28 having an inlet 29 and an outlet 30. 3| is the cable, which travels from right to left. The tubes gland may be removable so that different sizes may b inserted according to the diameter of the-cable used. The length of the tubes depends upon the 32 enters through the air heater 33a which consists of an electric heatingcoil and dry gland 33 and passes through three legs 34, 35 and 38 under vacuum. The U-tube 31 is filled with impregnating composition and sunk below the atmospheric datum line 38. There is a final barometric leg 39 to provide a vacuum impregnation following the pressure impregnation in the lower part of the U tube 31 and the space 40 is therefore evacuated. The cable emerges through a sealed tank 4| which is open 'to atmosphere. 42 is a pipe connecting the tank 4| with the first leg of the U tube 31 at atmospheric datum line.

We declare that what we claim is: 1. In a method of impregnating cables and like articles which comprises continuously passing the article through a treating zone in which itis subjected to heat and a pressure other than atmospheric. the step which consists in removing the 3. A method of treating cable which comprises continuously passing the cable through a dry seal, an evacuated heated drying zone, an impregnating zone, then passing the cable far below ground level through a U-shaped impregnating zone in which high superatmospheric pressure is obtained and removing the article from said zone through a. closely fitting surface sealed by a cooled viscous impregnating liquid.

FREDERICK PEEL. RUSSELL SWALE VINCENT. 

